o is the jQuery object generated from the inputID... o[0] should give the originating DOM element... it should not matter if the type is file...
can you post your code so I can check what is the problem here...

Yii is not the Linux kernel But looking back at the past version numbers for Yii, v1.1.9a could be problematic: I associate tha appended letter as a hotfix. But it looks like this has been used already to mark alpha-grade software (Yii v1.0a, v1.1.0a)

programmer /ˈprəʊgramə/, noun: a device that converts ►coffee into ►code